DESCRIPTION (provided by candidate): Emotion regulation is a critical component of social development and disruptions in the development of emotion regulation underlie many disorders. Although there is much research investigating the early development of emotion regulation in typically developing children, there is a paucity of research investigating these processes in children at risk for developmental disabilities. Children with autism spectrum disorder exhibit lower levels of emotion regulation as compared to typically developing children. Infant siblings of children with autism spectrum disorder are at an increased risk for the development of disorders and subclinical deficits that impair emotional functioning. Using a developmental psychopathology perspective, this longitudinal project proposes to examine the developmental trajectories of emotion regulation across the first three years of life in two groups of children: low-risk infants with a typically developing older sibling and high- risk infants with an older sibling with autism spectrum disorder. At 6 months of age infants and their mothers will participate in the face-to-face/still-face paradigm and the temporal associations between infant facial expressions and gaze direction will be examined. It is hypothesized that infants in the high-risk group will be less effective in regulating their emotions. For example, high-risk infants are expected to show higher negative affect during and after looking away from their parent during the still-face episode. Similar relationships will also be examined during the second and third year when toddlers participate in a frustrating prohibition task. The developmental trajectories of emotion regulation from 6 months to the third year will be examined. It is hypothesized that there will be developmental continuity in both groups. Finally, the project will use infant and toddler emotion regulation to predict individual differences in developmental outcomes during the third year, including social competence. The role of intrinsic (e.g. temperament) and extrinsic (e.g. parental sensitivity) factors in conditioning the aforementioned relationships will be explored. To achieve these goals, 150 infant siblings of typically developing children and 75 infant siblings of children diagnosed with autism spectrum disorder will participate in the project. This project is the first to systematically examine the emergence of emotion regulation in children at-risk for the development of varying levels of autism symptomatology. The present project is an important first step to understanding the origins of individual differences that set infants on diverse paths of vulnerability or resilience to later risk, and will provide the trainee with exceptional research experience and development in areas related to child health. PUBLIC HEALTH RELEVANCE: Investigating the emergence of emotion regulation among both low risk and high risk children will provide insight into how these processes go awry in children with autism spectrum disorder. Examination of the developmental trajectories of emotion regulation may help to inform early intervention programs and shed light on the emergence of autism symptomatology.